1. Field of the Invention
This invention generally pertains to the field of can openers and more particularly concerns an opener for use with pull top type cans.
2. Background of the Invention
Many sealed cans used for packaging and preserving foods and other products have pull-tab type closures. Two classes of pull-tab can closures are commonly used. In the first type, usually employed for packaging solid or semisolid materials, a can top is crimped along the upper edge of the can wall to form an elevated rim relative to the upper surface of the can top. The seam between the can top and the elevated rim is weakened by a score line which fully circumscribes the can top just inside of the elevated rim. A pull-tab riveted to the can top has a ring portion and a nose end diametrically opposed to the ring portion about the rivet fastener. In an original sealed condition of the can the pull tab lies flat against the can top. The rivet serves as a fulcrum for the pull-tab; as the ring portion is lifted away from the can top, the nose end presses down on the can top next to the seam, initiating a break in the seam along the score line. The ring portion of the tab is then pulled up so as to extend the rupture of the seam along the score line until the can top is lifted sufficiently to allow access to the contents of the can, or completely separates from the can. A second type of pull-tab closure, typically found on beverage cans where liquid contents require only a small opening in the can top, differs from the first in that the score line circumscribes only a small removable section of the can top, which provides a smaller opening adequate for dispensing liquid contents. A variant of this latter class is the so called pop-top type of closure where a small section of the can top is ruptured away and pressed into the can interior upon lifting of the tab, allowing liquid contents to be dispensed.
Many persons have difficulty opening cans with pull-tab closures with unaided hands. Persons afflicted with conditions which impair their manual dexterity, such as limited hand/finger strength, arthritis or injury, may find it painful or actually impossible to open such containers. Individuals with large hands and thick fingertips may have difficulty grasping and lifting the thin, flat ring of the pull tab away from the can top. Those with long finger nails risk breaking their nails while opening such cans. Healthy people may strain joints in their hands by repeatedly opening this type of can over a period of time. A person may be at risk of being injured by the sharp edges of the can lid. Also, the tab may break-off if it is stressed beyond its design limits, thus preventing access to the cans contents.
While various devices have been conceived to assist in the opening of pull-tab cans, a continuing need exists for an opener which is truly easy to use by virtually anyone and is specially adapted for opening cans in the first class described above, where the entire can top must be torn away in order to gain access to the contents of the can.